You still lose objective-based games. You have one maneuver unit and rely on a static gun-line. Especially in a high-terrain situation, it's only easier to negate the one-trick pony that is your army. It works well against a SM army trying to rush across the board with no thought, that's it.
You played a bad player if it took him until Turn 4 to get into melee. Beating a bad player with a one-trick pony who had no idea what he was facing is only going to hurt you in the long run.